Duplicator



| R. STARR I 2,146,998

DUPLI CATOR Feb. 14, 1939.

Filed March 16, 1938 INVENTOR. L e 0 Jf'a/r Patented Feb. 14, 1939UNITED STATES PATENT OFFICE Claims This invention relates to duplicatorsand the object of the invention is to provide a duplicator having asemi-cylindrical gelatin coated surface for producing copies and havinga roller movable through an arc to travel over the semi-cylindricalsurface in obtaining an imprint.

One of the particular objects of the invention is to provide asemi-cylindrical or arcuatetable over which a flexible gelatin coatedsheet is positioned, said sheet being held at one edge and means beingprovided for placing a tension on the other edge of said sheet tostretch the sheet into firm contact with the semicylindrical table.

Another object of the invention is to provide a duplicator provided withend plates and having a semi-cylindrical table mounted between theendplates and a U-shaped roller frame pivotally mounted on the axis ofthe semi-cylindrical table and turnable thereover to press theduplicating paper into contact with the printing surface.

A further object of the invention is to provide a semi-cylindrical tablehaving a flange at one edge over which the gelatin coated flexible sheetmay be engaged and having a pivoted arm adjacent the opposite edge ofthe semi-cylindrical table over'which the opposite edge of the saidstrip is engaged and spring means tending to turn the said arm on itspivot to stretch the gelatin coated flexible sheet tightly over thesemicylindrical table. 7

Another object of the invention is to provide a cam operated means forraising the tension member against the tension of the spring means toallow removal of the gelatin coated flexible sheet.

These objects and the several novel features of the invention arehereinafter more fully described and claimed and the preferred form ofconstruction by which these objects are attained is shown in theaccompanying drawing in which- Fig. 1 is a plan view of a duplicatorembodying my invention.

Fig. 2 is an end view thereof taken from the right end of Fig. 1. n

Fig. 3 is a section taken on line 3-3 of Fig. 1.

' Fig. 4 is an enlarged section taken on line 4-4 of Fig. 2.

Fig. 5 is an enlarged edge view of the gelatin coated flexible sheet forengagement over the semi-cylindrical table.

The device comprises a pair of semi-circular end members I and 2 shownin Figs. 1, 2 and 3.

These end members are cast and are each pro- 7 vided with a thickenedrim portion 3 as shown in'Fig. 3. The table is a semi-circular sheetmetal plate 4 which fits in grooves in the portions 3 of. the oppositeend plates and the end plates are connected together by a series ofthree bolts 5 shown in Figs. 1, 2 and. 3. The sheet metal tableisprovided with an inturned flange 6 shown more particularly at theleft. of Fig. 3 and the 5 duplicating surface comprises a semi-flexiblesheet 1 shown more particularly in Fig. 5 having a gelatin coating onthe outer face or surface 8. Secured to one. edge of the sheet 1' is achannel member 9v While a similar channel member ID is 10 secured to theoppositeedge of the sheet.

In applying the sheet to the sheet metal table, the channel 9 is hookedover the flange 6. at the edge of the sheet metal table and the flexiblesheet is laid over the table so. that the channel member I0 hangs belowthe inturnededge ll of the table opposite the flange 6.

A U-shaped tension member [2 having a crossbar I4 is pivotally mountedon the rod or bolt 5 at the left of' Fig. 3 and the cross-bar l4 may beengaged in the channel member [0 at the edge of the sheet I. Springs I5are provided for the arms l2 at the opposite ends of the cross-bar l4and these springs are connected to the end plates l and 2 topull thecrossbar l4 downwardlyand place a tension on the sheet I to hold it infirm contact with the semi-cylindrical table. As the outer surface 8 ofthe flexible sheet 1' is coated with gelatin, this provides a firmgelatin face for the duplicator.

In order to raise the crossbar I4 against the tension of the springs l5,a. shaft It extends between the end plates and a cam I1: is mounted ontheshaft [6 for each end arm l2. In the position shown in Fig. 3, thecam is turned to allow clearance between the cams and the arms I 2 toallow thefull tension of the springs l5 to be applied to the sheet. Inorder to release the sheet, a lever I8 is secured to one end of theshaft l6 and this lever is mounted in a recess IS in the end plate I Byturning this lever ill in a counterclockwise direction in the recess l9-the cams [1 are turned to raise the arms l2 and crossbar l4 out of thechannel member H1, at which time, by swinging the channel member Inoutwardly the flexible sheet 1 may be lifted off from thesemi-cylindrical table and disengaged from the flange 6. Thisarrangement is provided so that the flexible strip containing thegelatin surface may be removed from the device and wrapped up when notin use to prevent the gelatin face from drying out.

The end plates are each provided with an internal boss 20 and a U-shapedroller carrying frame 2| is provided which is pivotally mounted on theend plates by means of the screws 22 extending into the bosses 20. Thisframe comprising the end arms 2| is provided with a crossbar 23 to whichthe handle 24 is connected and a soft rubber roller 25 is providedhaving a shaft 26 extending into slots 21 in the end arms 2|. A block 28is secured in each end of the U-shaped frame by means of the screws 29shown in Figs. 2 and 4 and each block carries a coiled spring 30 havinga shoe 3l riding in contact with the shaft 26 and tending to press thesame toward the axis of rotation of the roll carrier frame which is thecenter of the bosses 20. In the position shown in full lines in Fig. 3,these springs 30 press the shaft ends 26 to the bottom of the slots 21and the crossbar 23 in this position rests on the rubber bumpers 32carried on extensions 33 of the end plates. In order to operate thedevice, a paper sheet 34 is provided which is laid against the gelatinsurface at the edge 35 to position the same on the duplicator. Afterthis edge has beenpositioned, the handle 24 is raised causing the roller25 to roll overthe sheet and as this roller is moved to the positionshown in dotted lines at the right of Fig. 3 the sheet is rolled in firmcontact with the gelatin surface on the flexible sheet 1. Uponcompletion of this rolling movement the handle 24 is returned to theposition shown in full lines in Fig. 3 against the rubber stops 32, atwhich time, the paper sheet 34 may be removed from the gelatin surfaceand the sheet will be printed in accordance with the printingon thegelatin surface.

As hereinbefore described, the lever 18 may be turned in acounter-clockwise direction in the recess ill to turn the cams i1 andraise the crossbar [4 out of the channel In at the edge of the flexiblesheet 'I and allow removal of the sheet. To replace the flexible sheet 1the channel 9 is engaged over the flange 6 of the semi-cylindrical tableand the sheet is laid over the table and the channel It) is broughtbeneath the crossbar .14 of the tensioning device. At this time, thehandle I8 may be returned to the position shown in full lines in Fig. 2and the cams will be turned to the position shown in full lines in Fig.3 thus allowing the springs IE to pull the crossbar l4 down into thechannel I and maintain a tension on the sheet. It will be noted that thehandle I8 is movable in a recess I9 in the end plate I. This is done sothat the end arms 2| of the roll carrier frame will clear the handlewhen turned to the opposite side of the device.

From the foregoing description it becomes evident that the device isvery simple and efllcient in operation, will maintain an even tension onthe gelatin coated sheet and will also maintain an even pressure on thepaper sheet due to the springs 30, will allow removal or replacement ofthe gelatin coated sheet and provides a device which accomplishes theobjects described.

Having thus fully described my invention, its utility and mode ofoperation, what I claim and desire to secure by Letters Patent of theUnited States is- 1. In a duplicator, a stationary semi-cylindricaltable provided with end plates, a frame pivoted on the end plates andturnable over the cylindrical casing, a pressure roller carried by theframe, rubber stop means for the frame carried by the end plates, aflexible sheet provided with a gelatin coating, a channel at each edgeof the flexible sheet, one channel being engaged over one edge of thesemi-cylindrical table and the sheet extending over the surface of thesemi-cylindrical casing, a U-shaped frame pivotally mounted within thecasing, the frame being provided with a crossbar engaging in the otherchannel of the flexible sheet, a spring tending to turn said frame onits pivot to apply tension to the flexible sheet, cam means for raisingthe U-shaped frame against the tension of the spring and means operablefrom the exterior of the table for turning the cam means.

2. In a duplicator, a pair of end plates, a stationary semi-cylindricaltable secured between the end plates, a flexible sheet provided with agelatin coating, a channel at each edge of the flexible sheet, onechannel being engaged over the edge of the semi-cylindrical casing, acrossbar arranged for engagement in the other channel, a pair of pivotedarms supporting the crossbar, a spring for each pivoted arm tending topull the same down and place a tension on the flexible sheet, a shaftextending between the end plates, a cam on the shaft for each pivotedarm, a lever for turning the shaft from the exterior of the casing, thearrangement being such that as the shaft is turned the cams will movethe pivoted arms against the tension of the springs to disengage thecrossbar from its channel on the flexible sheet.

3. In a duplicator, a stationary semi-cylindrical casing provided withend plates, a U-shaped frame member pivotally supported in the endplates on the axis of the semi-cylindrical casing, a gelatin coatedflexible sheet positioned on the semi-cylindrical casing, one edge ofthe sheet being anchored to the casing, means for applying a tension tothe opposite edge of the sheet to maintain the same in tight contactwith the semicylindrical casing, a pressure roller carried by theU-shaped frame member and movable over the casing by turning the framemember, each end plate being provided with an extension and a rubbercushion on each extension engaged by the U-shaped frame member as it isturned to one end of its path of travel.

4. In a duplicator, a semi-cylindrical sheet metal table, supportingmeans therefor, a gelatin coated flexible sheet having one enddetachably secured to an edge of the table, tensioning means for theother end of the sheet adjacent the opposite edge of the table, an armpivoted to the axis of the table, a roller carried by the arm andmovable across the gelatin sheet, said supporting means terminating in ahorizontal plane on the opposite side of-the pivot point from thatoccupied by the table and adapted to support the device in stationaryposition on a plane surface for the printing operation by the roller.

5. In a duplicator, a semi-cylindrical sheet metal table, a gelatincoated flexible sheet having one end detachably secured to an edge ofthe table, tensioning means for the other end of the sheet adjacent theopposite edge of the table, an arm pivoted at the axis of the table, aroller carried by the arm and movable across the gelatin sheet, asupporting means for the semi-cylindrical table terminating in a planeon the opposite side of the axis from that occupied by thesemi-cylindrical sheet and providing a means for supporting the table ina stationary position, the roller being mounted on the arm in a mannerto permit limited radial movement, and spring means resisting radialmovement of the roller.

LEO R. STARR.

